From Epicurus and His Philosophy:
Page 67 - Epicurus was in revolt also against the teachings of Democritus, Socrates, Plato, and the rest concerning the function of philosophy. The Phi Beta Kappa idea that "Philosophy is the guide of life" was already commonplace, but no one was interpreting it very practically, To the great atomist Leucippus, Epicurus even denied right to the name of philosopher, because he concerned himself with physics to the exclusion of ethics. The ground upon which this was denied was neatly expressed: "Vain is the word of that philosopher by which no malady of mankind is healed." This position was arrived at by way of the analogy with medicine, itself an inert commonplace in the then current philosophies. He proposed to put life into it: "For just as there is no profit in medicine unless it expels the diseases of the body, so there is none in philosophy either unless it expels the malady of the soul." With Democritus himself Epicurus was impatient became or his implicit skepticism, which to him was a sort of pessimism paralyzing to action.
page 175 - Concurrently with the labors of the tragedians over the problem of fate and freedom the physicists had been busy erecting an edifice of thought of which the end result was a kind of fatalism even more shocking to the sensibilities of Epicurus. We still possess his pronouncement upon the topic: "It were better to follow the myths concerning the gods than' to be a slave to the Necessity of the physicists, for the former presumes some hope of appeasement through worship of the gods while the latter presumes an inexorable Necessity." The crime of the physicists, in his judgment, had been their failure to deal with the problem of freedom, and their offense was at its worst in the case of the atomists, who found the sole cause of motion and change in the universe to be the motion of the atoms. On this point the feelings of Epicurus were so intense that he denied to Leucippus even the name of philosopher.
page 306 - The first impulse to genuine love of mankind seems to have had its source neither in philosophy nor political theorizing but in Hippocratic medicine. One of its sayings is well known: "Where there is love of mankind there will be love of healing," That the inspiration of Epicurus came to him by this avenue there can hardly be a minimum of doubt. His own mission was conceived to be one of healing: "Vain is the word of that philosopher by which no malady of mankind is healed, for just as there is no benefit in the art of medicine unless it expels the diseases of men's bodies, so there is none in philosophy either unless it expels the malady of the soul." It is on this principle that he denied to Leucippus the right to the name of philosopher and chiefly on the same ground that he broke with Democritus, who seemed in the opinion of his great disciple to impose upon men a paralyzing law of physical necessity.